linux-kernel - Re: [patch] power, xen64: fix PM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <48751E34.3060100@goop.org>
Date:	Wed, 09 Jul 2008 13:23:16 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
CC:	Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>,
	x86@...nel.org, Stephen Tweedie <sct@...hat.com>,
	Eduardo Habkost <ehabkost@...hat.com>,
	Mark McLoughlin <markmc@...hat.com>
Subject: Re: [patch] power, xen64: fix PM_SLEEP build dependencies

Rafael J. Wysocki wrote:
> On Wednesday, 9 of July 2008, Ingo Molnar wrote:
>   
>> * Rafael J. Wysocki <rjw@...k.pl> wrote:
>>
>>     
>>>> This combination actually doesn't make sense whatsoever.
>>>>
>>>> PM_SLEEP depends (indirectly) on PM and the fact that it's possible 
>>>> to use a .config violating this dependency is a build system 
>>>> problem, really.
>>>>         
>>> Your patch is correct, though. :-)
>>>       
>> yes, that combination doesnt make sense in -git, but tip/xen64 tries the 
>> !PM && PM_SLEEP combination - see the patch below.
>>     
>
> It shouldn't.  There are many things compiled if PM is set that PM_SLEEP
> depends on, most importantly ->suspend() and ->resume() callbacks of almost
> all drivers.  Ignoring this dependency is asking for trouble.
>   

Doesn't that mean that PM_SLEEP should depend on PM?

> I don't like this.
>
> I'll have a look at the remaining related patches and see what can be done.
>
> Jeremy, what exactly do you need the !PM && PM_SLEEP combination for, BTW?
>   

See drivers/xen/manage.c.  On the Xen save/restore path, I call 
device_(suspend|resume|power_down|power_up)(), primarily to get the 
system timers into a good state after the machine has been away for a 
while.  Xen doesn't have a general dependency on the rest of the PM 
infrastructure.

    J
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/